Mow strips can be made from any solid material used to separate the lawn from a planting bed. They allow a law mower to trim the grass all the way to edge of the lawn without having to use a string trimmer. Mow strips are usually made from concrete but can also be made from pavers
Thin posts (tiki torches) along walkway with round lights or chinese lantern style stringers between. Up high enough to stop cats/dogs playing with them or people tripping over them, cemented into ground with rocks if you have a problem with things being dug up.